synaptic transmission

• 1 St stage synaptic transmission

  an action potential (electrical impulse) reeaches the atron terminal of a reason which causes vesicles to release their contents (neurotransmitters) in to the synaptic gap.
• 2nd step of synaptic transmission

  Neurotransmitters diffuse across the synaptic gap before binding to specialised receptors on the post-synaptic neuron
• what happens when NTS lead to excitation of the post-synaptic neuron

  This refers to chen excitatory Leg. dopamine) bind and provide excitatory post synaptic potentials (EPSPs) . EPSPs increase the positive charge of a post-synaptic neuron, making it more likely to fire
•  what happens when NTS can lead t inhibition of the PSN

  This refers to when inhistory NTS (e.g. serotonin) bind and provide inhibitory post. synaptic potentials (IPSPs). IPSP s increase the negative charge of a post - synaptic neuron, making it less likely to fire
• Describe the summation process (the 4th step of synaptic transmission)

  If the net effect on the post-synoptic neuron is inhibitory lie. there are more IPSPs), it will not five an action potential. If the net effect is excitatory (ie. there are more EPS Ps), an action potential will be fired.
• what is the last step of synaptic transmission

  Once neurotransmitters bind to their specialised post-synaptic receptors and exert their excitatory or inhibiting effects, they dissociate (un-bind) and return to the pre-synaptic neuron's axon terminal through re-uptake transporters. Any remaining inches synaptic gap will be broken down by enzymes
• How drugs can increase synaptic transmission

  By blocking me-uptake transporters. This means less N TS in the synapse, allowing them to continue binding to P-SR and exerting their inhibitory or excitatory effects.
• How can drugs decrease synaptic transmission

  By not exerting any effect. They therefore block neurotransmittersfrom binding to receptors on the post-synaptic neuron. Thus neurotransmitters cannot exert their inhibitory or excitatory effects e.g. antipsychotics